GroupingSets Unary Logical Operator¶

GroupingSets is a BaseGroupingSets that represents the following high-level SQL-only operators (in a logical query plan):

GROUPING SETS SQL statement
GROUP BY ... GROUPING SETS SQL statement

Note

grouping and grouping_id standard functions can only be used with grouping analytics clauses (incl. GroupingSets).

Spark Structured Streaming Not Supported

Grouping Sets is not supported on streaming DataFrames (that is enforced by UnsupportedOperationChecker).

Creating Instance¶

GroupingSets takes the following to be created:

GroupingSets Indicies
Flat GroupingSets Expressions
User-Specified GroupBy Expressions

GroupingSets is created using apply utility only.

Creating GroupingSets¶

apply(
  groupingSets: Seq[Seq[Expression]]): GroupingSets // (1)!
apply(
  groupingSets: Seq[Seq[Expression]],
  userGivenGroupByExprs: Seq[Expression]): GroupingSets

userGivenGroupByExprs is an empty collection (Nil)

apply computes the GroupingSet indicies and creates a GroupingSets.

apply is used when:

AstBuilder is requested to parse GROUPING SETS or GROUP BY ... GROUPING SETS SQL statements